Cyclic recording system by the use of an elastomer in an electric field

ABSTRACT

The applications of elastomers to various imaging techniques are described which may be used for the cyclic recording, storage and subsequent erasure of optical information. Several embodiments of the invention are described, all of which form images by the elastic deformation of a thin elastomer layer. The pattern of the surface deformation, in general, follows the light distribution of the optical image being recorded. This image is formed on a photoconductive layer which is adjacent to, or integral with, the elastomer layer. An electric field is placed across the elastomer and the photoconductor layers, the field being modulated by the action of the image light on the conductivity of the photoconductor and provides the mechanical force necessary to deform the elastomer. Once the elastomer surface has deformed, it will in general remain deformed as long as the field across it is maintained; the image recorded, accordingly, being stored. Removing the electric field allows the elastomer to relax and the image is consequently erased. Reversing the field increases the rate at which the image is erased. A new image may now be formed, and the cycle started over again. Such an elastomer material is capable of a great many recording/storage/erasure cycles.

United 1 States Patent I 1191 Sheridon 11 3,842,406 [451 Oct, 15, 1974 1i CYCLIC RECORDING SYSTEM BY THE USE OF AN ELASTOMER IN AN ELECTRICFIELD [75] Inventor: Nicholas K. Sheridon, Fairport, NY.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

22 Filed: Nov. 24, 1972 21 App1.No.:309,379

Related U.S. Application Data [60] Division of Ser. No. 101,729, Dec.28. 1970, Pat. No. 3,716,359, which is a continuation of Serf No.23,649, March 30, 1970, abandoned.

Primary ExaminerTerrell W. Fears Attorney, Agent, or FirmJames J.Ralabate; Dav1d C. Petre; Gaetano Maccarone 57] ABSTRACT Theapplications of elastomers to various imaging techniques are describedwhich may be used for the cyclic recording, storage and subsequenterasure of optical information. Several embodiments of the invention aredescribed, all of which form images by the elastic deformation of a thinelastomer layer. The pattern of the surface deformation, in general,follows the light distribution of the optical image being recorded. Thisimage is formed on a photoconductive layer which is adjacent to,or-integral with, the elastomer layer. An electric field is placedacross the elastomer and the photoconductor layers, the field beingmodulated by the action of the image light on the conductivity of thephotoconductor and provides the mechanical force necessary to deform theelastomer. Once the elastomer surface has deformed, it will in generalremain deformed as long as the field across it is mainmined; the imagerecorded, accordingly, being stored. Removing the electric field allowsthe elastomer to relax and the image is consequently erased. Reversingthe field increases the rate at which the image is erased. A new imagemay now be formed, and the cycle started over again. Such an elastomermaterial is capable of a great many recording/storage/erasure cycles.

50 Claims, 13 Drawing Figures LIGHT SOURCE IMAGING SANDWICH OBJECTRECORDING IMAGE FIG. 60

LIGHT SOURCE SANDWICH READING-OUT IMAGE LIGHT SOURCE IMAGE PLANEPATENTEU DU 1 51974 3,842,406

SHEEI t (If 5 BEAM SPLETTER IMAGING SANDWICH LASER OBSERVER VIRTUALIMAGE lMAGING SANDWICH F/GI/Ob CYCLIC RECORDING SYSTEM BY THE USE OF ANELASTOMER IN AN ELECTRIC FIELD CROSS REFERENCE This application is adivision of copending application Ser. No. 101,729, filed Dec. 28, 1970,now U.S. Pat. No. 3,716,359 which is a continuing application of mycopending application under the same title filed Mar. 30, 1970, Ser. No.23,649 now abandoned.

BACKGROUND OF THE INVENTION Prior art thermoplastic surface reliefimaging taught the recording of images by means of deformations in anotherwise smooth thermoplastic surface. The image information isrecorded as a hill and valley structure on this surface. Light reflectedor transmitted through this surface may be used to make the recordedimage visible because such light will be scattered or diffracted by thisstructure. Three basic types of thermoplastic surface relief imaging maybe distinguished.

Historically, the first of these is frost imaging" which may be seen inU.S. Pat. Nos. 3,196,009, 3,196,011, 3,258,336 and 3,196,008 as a few ofmany examples. Frost imaging has been practiced in the past by creatinga voltage pattern across a thin layer of insulating thermoplastic. Thisvoltage pattern is usually established by means of an adjacent layer ofphotoconductor material although the thermoplastic itself may be madephotoconductive. In use, the electric field is placed across thethermoplastic/photoconductor sandwich or across the photoconductivethermoplastic. The light intensity pattern of the image formed on thephotoconductor now creates a varying electrostatic field.

lt has been observed by this inventor and others that been placed, willpreferentially deform in a pattern exactly matching the spatialfrequency variations in this field; provided these variations arepredominately composed of spatial frequencies in the neighborhood of thecharacteristic or resonant frequency of the layer. For moderate valuesof the electric field this resonant frequency commonly has the valuefzT, where T is the thickness of the liquid layer. Where the fieldpattern varies much more slowly than this, the surface will tend towrinkle or randomly deform; such wrinkles having characteristic spatialfrequencies in the neighborhood of /&T and being referred to as frost.Hence, images having spatial frequencies within the region of theresonant frequency of the deformable surface will be faithfullyreproduced by deformations of this surface. Images, on the other hand,having spatial frequencies much lower than this resonant frequency willtend to form frost in the regions of greater illumination. Inconjunction with a Schlieren optical or other suitable system, goodquality images may be reconstructed from frost deformations. However,the inherent noise structure of the frost image is objectionable forsome applications.

The second type of surface relief imaging was taught by Urbach and iscommonly called screened frost. See U.S. Pat. Nos. 3,196,012 and3,436,216. This imaging technique is capable of recording surfacedeformation images of spatial frequency much lower than the resonantfrequency of the deformable layer. Urbach has shown that by interposingan absorption type line grating of spatial frequency close to theresonant spatial frequency of the deformable surface between the imagebeing projected on the photoconductor and the photoconductor itself, thesurface will deform without frost in those regions where thephotoconductor is illuminated. The solid areas, i.e., low spatialfrequency areas, of this screened frost image are now filled, not withfrost, but with remnants of the screen. If these screen remnants areobjectionable, they can be removed by subsequent spatial filtering or bytechniques further taught by Urbach.

The third type of surface relief imaging is actually a variant of thefirst two, but because of its importance deserves to be treatedseparately. This relates to the re cording of holograms on a deformablesurface structure and has been taught by Cathey, for bleached gelatinemulsions and later by Urbach for thermoplastic/- photoconductorsandwich structures. See U.S. Pat. No. 3,560,205, Imaging System, Ser.No. 521,982, filed on Jan. 20, 1966. A hologram is a recording of theinterference pattern between two coherent light beams. One light beamusually contains information about an object and the other is areference beam, generally of simple structure. The interference patterngenerally resembles a somewhat garbled image of a screen. If the spatialfrequency of the screen approximates the resonant frequency of the thinliquid layer, the surface would deform along the structure of theinterference pattern and little noise would be generated.

All of the above imaging techniques involve the deformation of a thinheat or solvent vapor softenable plastic layer to record imagedeformation. They may, in principle, be recycled by applying heat orsolvent vapors to soften the plastic and allow the recorded image toerase. Ordinarily, the surface would be allowed to solidify again bycooling or vapor ventilation and another image could be formed on it asbefore. However, these systems cannot be cycled very rapidly or veryconveniently. Moreover, cycling requires the expenditure of solvents, orlarge amounts of power. Further, it has been repeatedly observed thatstate of the art plastics do not erase completely, due to chemicalchanges associated with the development process; and, hence, only alimited number of imaging cycles can be obtained with these materials.Accordingly, there is a continuing need for surface deformation imagingsystems that will store information and can be repeatedly cycled rapidlyand conveniently, with low power consumption.

OBJECTS OF THE INVENTION It is, therefore, an object of the presentinvention to provide an optical imaging system which overcomes the abovenoted deficiencies and satisfies the abovenoted wants.

It is another object of the present invention to provide an opticalimaging system that will record optical information, store it, erase itand do these things many times.

It is another object of this invention to provide an optical imagingsystem capable of recording the high spatial frequency opticalinterference patterns characteristic of holograms, as well as the lowerspatial frequency images commonly characteristic of non-coherent lightimages.

It is another object of this invention to provide an optical imagingsystem which records a surface relief image with light incident from oneside of the imaging member and to simultaneously allow light of the sameor different wave length or the same or different intensity incidentfrom the opposite side of the member to form a similar optical image forpurposes of wavelength change, image projection, image intensificationand other optical transformations.

It is another object of this invention to provide an optical imagingsystem which records a surface relief image on an essentiallytransparent imaging member, such that images may be recorded andreformed by transillumination.

It is another object of this invention to provide an optical imagingsystem which will be capable of recording images most efficiently withina narrow range of spatial frequencies, or within several narrow rangesof spatial frequencies.

BRIEF SUMMARY OF THE INVENTION In accomplishing the above and otherdesired aspects of the present invention, Applicant has invented improved apparatus and methods for a fully cyclycable imaging device onwhich images may be recorded, stored for short periods of time anderased at will. The inventor provides an imaging member which comprisesa substrate that is conductive or has a conductive surface. Coated onthis surface is a photoconductive layer whose conductivity is dependentupon illumination, and coated above this is an elastomer layer. Inanother embodiment a separate photoconductor layer is not used, butrather the elastomer layer is photoconductive. A deformable conductivelayer including either a flexible conductive member, a conductiveliquid, a conductive gas or a layer of elastrostatic charge is placedcontiguous to the surface of the elastomer. An electric fieldestablished between the deformable conductive layer and the conductivesubstrate increases in those regions where the photoconductive layer isexposed to electromagnetic radiation (hereafter referred to as light)causing the elastomer to deform in those regions. Two types of imagingbehavior have been observed. In the case of very compliant elastomersand large electric fields the elastomer remains deformed while theelectric field is maintained. This deformation is not substantiallyaffected by subsequent illumination of the photoconductor, and thus maybe said to be electrically locked. The recorded image information maynow be read out at leisure with any brightness illumination. Thedeformation is removed by removing the field, allowing the elastomer torelax. By reversing the field across the elastomer instead of removingthe field, the image may be erased much more quickly. A new image maynow be formed. It is to be noted, however, that the electrical lockingproperty of the elastomer exists only above a certain value of theelectric field. Below this field threshold value the image erases slowlyespecially upon exposure of the photoconductor to light. Thisconstitutes the second type of imaging behavior. Here again the imagemay be rapidly erased by removing or reversing the field across theelastomer.

Because thin layers of elastomers behave in a manner similar to thinlayers of viscous liquids for small deformations, an elastomer imagingdevice, much like a thermoplastic imaging device, is capable of formingthree types of image: frost images, screened frost im ages and limitedspatial frequency or holographic images. However, because an elastomeris, in general, es-

sentially an incompressible material and because the extent of itspossible deformation is limited by internal elastic forces as well assurface forces, a thin elastomer layer can exhibit an appreciableresponse to surface force patterns lying only within a limited spatialfrequency bandwidth. The greatest response is in the neighborhood of theresonant frequency, usually equal to approximately lT as in the case ofthermoplastics. When an elastomer is exposed to an image having the bulkof its information within the spatial frequency response of theelastomer, the elastomer will record that image very well. Such imagesare of great interest primarily for holography and for recordingprinted, written or numeric information of high contrast. When such anelastomer layer is exposed to an image composed of spatial frequencieslower than the recording band of the elastomer, the brightly illuminatedareas of the elastomer will deform into a random deformation patternsimilar to the frost of the thermoplastic recording. The spatialfrequency of the frost deformation lies within the recording bandwidthof the elastomer, and the frost will randomly scatter incident light.Less brightly illuminated areas will not frost and hence will notscatter. Such an image is called a frost image and, as in thethermoplastic case, is sometimes objectionable for some applicationsbecause of its inherently noisy structure.

The third type of surface relief image called screened frost is suitablefor recording images having spatial frequencies substantially lower thanthe resonant deformation frequency of the elastomer layer. This isformed by placing an absorption type line grating between the projectedimage light and the photoconductor upon which it is imaged. Theelastomer will now deform along the pattern of this high spatialfrequency screen in those areas where it is illuminated and, therefore,will not form frost. The screened surface relief image will then consistof segments of the shadow of the screen. The image obtained byilluminating the elastomer will, thus, have a fine structure of linessuperimposed upon the original image that was recorded. If this linestructure is objectionable, it may be removed by suitable opticalfiltering techniques well known in the art.

For the imaging structures described herein, the preferred location ofthe screen, eg a line grating, is immediately adjacent to aphotoconductive layer in the imaging structure. Other types of screensthat may be similarly located are described in two copendingapplications, both titled Methods of Organized Thermoplastic Xerographyand Photoreceptor Structure Therefor, one in the name of Lloyd F. Beanand the other in the name of John C. Heurtley, filed Sept. 18, 1970, andSept. 18, 1970, Ser. No.s 73,406 and 73,317, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of theinvention as well as other objects and further features thereof,reference is made to the following detailed description taken inconjunction with the accompanying drawings wherein:

FIG. 1 is a side sectional view of the elastomer imaging apparatus of afirst embodiment of the present invention;

FIG. 2 is a side sectional view of the elastomer imaging apparatus of asecond embodiment of the present invention;

FIG. 3 is a side sectional view of the elastomer imag ing apparatus of athird embodiment of the present invention;

FIG. 4 is a side sectional view of the elastomer imaging apparatus of afourth embodiment of the present invention;

FIG. 5 is a side sectional view of a multilayered elastomer inaccordance with the principles of the present invention;

FIGS. 6 to 10 are partly schematic, partly side sectional view ofvarious physical applications of the principles of the presentinvention;

FIG. 11 is a schematic, perspective view of a computer print-out systemsusing the imaging structures and methods of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The term elastomer in the variousforms used herein is defined as a usually amorphous material whichexhibits a restoring force in response to a deformation; that is, anamorphous material which deforms under a force, and, because of volumeand surface forces, tends to return to the form it had before the forcewas applied.

The first embodiment of the present application shown in FIG. 1 is anelastomeric imaging device in which charges are placed on the surface ofthe elastomer by means of a corona discharge. Modified forms of a coronadischarge device are well known in the art as coratrons or scoratrons.With such a device, positive or negative ions are produced by a highvoltage field in a gas and deposited upon the surface.

The apparatus of FIG. 1 includes a substrate 1 which is eitherconductive or is conductive on one surface thereof. It will mostgenerally be a transparent substrate although, in those cases wherelight is to be reflected from the elastomer to reconstruct an image, itmay be opaque. Substrate 1 may also have a highly reflective mirrorfinish so that reconstruction light will pass through the elastomer,reflect from it and pass through the elastomer once again; therebyobtaining twice the modulation that a transmissive device will impart.If the substrate is to be transparent, commonly available NESA glasscould be used. This is a tin oxide coated glass conductive on thesurface corresponding to layer 2 in FIG. 1. Alternatively, it could be apiece of transparent glass with a metallic conductive layer on thesurface, a layer thin enough to be transparent. If transparency of thesubstrate is not important, a metallic substrate may be used. Thesubstrate could be a plastic material such as Mylar or acetate, ifflexibility were desired. If substrate 1 is not conductive, layer 2which is a conductive layer must be added. This is normally atransparent, or partially transparent layer.

The photoconductive layer 3 is a material which will allow the passageof more electric charge in those regions which are exposed to light.This definition of a photoconductor may be extended to any materials inwhich the conductivity is inhibited by the presence of light. Such aphotoconductor is often a mixture of polyn-vinyl carbazole and asensitizing dye. The thickness of the photoconductor will probably rangefrom 0.1 microns to 200 microns, depending largely upon the spatialfrequency of the information to be recorded.

The elastomer layer 4 may be of a class of elastomeric soft solidmaterials for use in this application including both natural, such asnatural rubbers and synthetic polymers which have rubber likecharacteristics, i.e., are elastic and include materials such asstyrenebutadiene, poly-butadiene, neoprene, butyl, polyisoprene, nitrileand ehtylene propylene rubbers. Preferred elastomers for use in thisapplication include: water based gelatin gels and dimethylpolysiloxanebased silicone gels. These materials may be coated on the photoconductoras monomers and polymerized in place or they may be coated on thesurface from solutions in volatile solvents which will evaporate andleave a thin uniform layer. In general, these materials should beresonably good insulators, having volume resistivities in excess of l0ohm'centimeters.

The preferred elastomer is a transparent composition comprising anelastomeric dimethylpolysiloxane silicone gel made by steps includingcombining about one part of Dow Corning No. 182, silicone resin pottingcompound and anywhere from about zero to about thirty parts of DowCorning No. 200 dimethylpolysiloxane silicone oil. Suitable resinsinclude transparent flexible organosilonane resins of the type describedin US. Pat. No. 3,284,406 in which a major portion of the organic groupsattached to silicon are methyl radicals.

The thickness of the elastomer layer will range from approximately 0.1microns to approximately 2,000 mi crons, depending upon the spatialfrequency of the information required. Various optical properties of thedevice may be enhanced by a suitable selection of the elastic modulus ofthe material used. For example, a stiffer elastomer will recover morerapidly from an image when the electric field is removed, that is, maybe erased more quickly. On the other hand, a material having a lowelastic modulus will be capable of greater deformations and hencegreater optical modulation for a given value of electric field.

The corona charging apparatus 5 may be a stationary charging unitprovided such a unit provides enough uniformity of charge deposition, orit may be a scanning system. This device places positive or negativecharges on the surface of the elastomer. The voltage drop across theelastomer photoconductive sandwich will lie in the range of l to 25,000volts depending on the modulus of elasticity of the elastomer and itsthickness, as well as certain properties of the photoconductor.Particular types of scoratron devices which have been found useful incorona charging are disclosed in the Vyverberg US. Pat. No. 2,836,725and the Walkup US. Pat. No. 2,777,957 and assigned to the same assigneeas herein. The device should be placed in such a way that will causeminimal interference with light reaching the photoconductor and lightused to reconstruct the image. It may be appreciated that substrate 1 orlayer 2 in FIG. 1 need not be conductive in the corona charging modesince double sided corona charging may be used to charge a surface ofboth layer 1 and the elastomer 4, the two charging devices, one on eachside of the imaging member, are oppositely charged and are traversedmore or less in register. In other words, a second corona chargingdevice may be used to obviate the need for a conductive layer 2 orsubstrate 1.

In operation, the corona charging apparatus 5 lays charges down on theelastomer layer 4. The sandwich in FIG. 1 is then exposed, eithersimultaneously or subsequently to the charging step depending upon theability of the elastomer to hold charge on its surface, to a light fieldwhich must come from the right if substrate 1 is opaque. If substrate 1is transparent, the light may propagate from either the right or theleft. Substrate 1, or the alternate layer 2, are grounded therebycreating an electric field across the photoconductor and elastomercombination. This electric field induces a flow of charge in thoseregions of teh photoconductor which are exposed to light, varying theelectric field across the elastomer. The mechanical force of theelectric field across the elastomer causes it to deform. Thisdeformation will proceed until the forces of the electric field arebalanced by the surface tension and elastic forces of the elastomer. Atthis point, the deformation stops and becomes stable as long as theelectric fields across the elastomer are maintained. This deformation isdifferent from that occurring in thermoplastic materials in that theelastomer deformations are independent of any developing step such asheat and/or solvent softening steps employed with thermoplasticmaterials. Another difference between elastomer and thermoplastics isthat the elastomer deformations assume a definite limit for a givenelectric field because elastic forces oppose the deformation. Thethermoplastic deformations do not encounter such a definite limit for agiven field as long as the thermoplastic is maintained in a softenedcondition. To erase this image, the field across the clastomer isremoved; to erase more quickly the field across the elastomer isreversed. Now the device is ready to accept another image.

In FIG. 2 is a second embodiment wherein an electric field is createdacross the elastomer 9 and photoconductor layer 8 by means of a thincontinuous conductive layer 10 on the surface of the elastomer, whichlayer is flexible enough to follow the deformations of the elastomer. lnthe case where this layer is highly reflective, this apparatus willutilize the readout light with great efficiency. If the layer is opaque,light propagating from the left may be used to form the surfacedeformation image, while simultaneously light propagating from the rightmay be used to reconstruct the image. The light sources used may be ofdifferent wavelengths and/or intensities and/or one light source may becoherent and the other noncoherent. Hence, this device may be used toconvert an image formed in one wavelength into an equivalent imageformed in a different wavelength. Also, if the readout light incidentfrom the right is very much more intense than the imaging light incidentfrom the left, the apparatus shown in FIG. 2 will provide greatamplification of an input image, such amplified light being used, forexample, for large panel displays. Furthermore, the reconstruction lightmay be coherent, e.g., that produced by a laser, so that imageprocessing steps may be performed on the surface deformation image whichis formed with non-coherent light propagating from the left. On theother hand, the light giving rise to the surface deformation image maybe coherent light while the reconstruction light may be non-coherent.This latter case is desirable because noncoherent light is more pleasingto the human eye and current coherent light generators are limited toproduction of light within narrow wavelength bands, i.e. one color suchas red. A reason for having coherent light for forming the surfacedeformation image arises when it is the reconstruction light for formingimages with holograms. Therefore, the present device may have aholographically reconstructed image projected onto it forming a surfacedeformation image that is viewed with non-coherent light ofsubstantially greater intensity as suited for large panel displays.

In FIG. 2, as it was for the embodiment shown in PEG. 1, substrate 6 maybe transparent or opaque depending upon use. Conductive layer 7 isoptional and is used if substrate 6 is not conductive. lf substrate 6 istransparent then the conductive layer 7 would generally also betransparent. Over the conductive layer 7 is coated the photoconductivelayer 8. Over the photoconductive layer 8 is the elastomer layer 9. Thethin conductive layer 10 must be flexible enough to follow thedeformations of the elastomer layer 9. If the conductive layer 10 isopaque, for example, a thin metal film, the substrate 6 and conductivelayer 7 must be transparent to allow image information to reach thephotoconductive layer 8. In this case, image information can be read outcontinuously if the readout light is incident from the right. If theconductive layer 10 is transparent, light may be reflected from itssurface or the device may be used in transillumination, providedsubstrate 6 and layer 7 are transparent.

Conductive layer 10 may be a thin layer of gold, or a thin layer ofindium, or a combination of the two, or other suitable metal layers. Thethickness of the metallic layers would normally be between approximately50 angstroms to several thousand angstroms thick, depending on thedesired flexibility, and the necessary conductivity. A transparentconductive layer could also be used, such as Dow Corning resin ECR 34may be coated on the surface of the elastomer 9. Other conductivelayers, such as may occur to one skilled in the art, may also be usedwithin the principles of the present invention. To form and lock thedeformation image, the values of voltage between substrate 6 and conductive layer 10 would be approximately between 1 and 25,000 volts,depending on the thickness, and other characteristics, of elastomer 9.

The requirements for conductive layer 10 include: sufficientconductivity to become an equipotental surface when connected to anelectrical energy source; sufficient flexibility to follow thedeformations of the elastomer; sufficient fatigue resistance towithstand numerous and rapid formations and erasures of surfacedeformations; and, in some cases, high opacity and reflectivity as whenbeing read out by a high intensity light source to which thephotoconductive layer is sensitive.

The preferred materials for conductive layer MI include gold and indium.The layer is formed by steps including vapor depositing the materialsonto the elastomer which involves heating a material to or above itsmelting point and condensing the vapors on the desired surface. Thistechnique is well understood in the art and conventional practices arefollowed in evaporating and condensing the materials. However, a problemassociated with shrinkage of a condensed metal layer is overcome bynovel techniques in order to fabricate a conductive layer 10 meeting theabove requirements. Vapor deposited metals tend to shrink, i.e.contract, as they cool and at some thermo-energy state the metal layertends to break up or crack making the layer discontinuous. This break upof a metal layer is referred to herein as mud-cracking since mud cracksare broadly descriptive of the appearance of the layer after shrinkage.The instant novel technique includes vapor depositing a second metalover the first before the first has mudcracked. The two materials may bevapor deposited simultaneously. The second metal is selected so as tohave a lower melting point than the first deposited metal. The finalproduct is a continuous layer meeting the above requirements which yetdoes not experience mud cracking over a wide range of temperatures. Thedescribed layer may include portions where the two metals (or othersuitable materials) are coated one over the other, portions where thetwo metals are intermixed macroscopically as well as microscopically(e.g., to form an alloy) and portions where they reside side by side.Naturally, additional materials may be added to the layer to enhance orsuppress particular characteristics.

One theory, to which this invention is not limited, that explains whymud cracking is suppressed in the above multiple component layer, isconnected with the relative mobility of atoms at the surfaces of thedifferent materials. The atoms of high melting point materials normallyexhibit low surface mobility which gives rise to the mud cracking whenthe metals are coated over an elastomer. The atoms of lower meltingpoint materials exhibit by comparison much greater surface mobility andtheir presence enables the stresses developed in the high melting pointmaterial to be relieved.

The preferred materials of gold and indium have high and low meltingpoints respectively. Mud cracking is usually observed in vapor depositedgold layers within minutes after cooling to room temperatures. Thisusually provides ample time to vapor deposit the indium onto the goldlayer. An example of a highly successful coating is one formed bydepositing from 50 to several thousand angstroms of gold followed bydepositing onto this gold layer from 50 to several thousand angstroms ofindium. The resultant layer is continuous and exhibits no mud crackingover a wide range of temperatures. The indium is particularlyadvantageous because it increases the opacity of the resultant layerand, because of its silver appearance, enhances the reflectivity of thelayer.

It is noted that indium by itself is not a highly efficient material forlayer 10 because of poor conductivity. The poor conductivity is peculiarto low melting point materials because they tend to form islands duringcondensation which do not join together into a continuous layer of areasonable thickness. Accordingly, it is observed that vapor depositionof single materials (or alloys thereof), whether high or low meltingpoint materials, yields layers that are less satisfactory than the layercomprised of high and low melting point materials.

Other suitable high melting point materials besides gold includealuminum, silver, magnesium, copper, cobalt, iron, chromium, nickel andothers. Aluminum has the further desirable property of being highlycorrosion resistant. Other suitable low melting point materials besidesindium include gallium, cadmium, mercury, lead and others. Cadmium byitself exhibits a low tendency to mud cracking.

Of course, the foregoing problems of mud cracking and island forming maynot arise if the conductive layer 10 is formed by chemical reaction,precipitation out of a solution, electrophoresis, electrolysis and/orother techniques.

Over the conductive layer 10 in FIG. 2 may also be an optionaltransparent insulating layer of oil. Its purpose is to make lessstringent the fabrication requirements for this apparatus. The presenceof pin holes in the elastomer layer 9 may cause the apparatus in FIG. 2to short circuit, possibly destroying its performance. The addition ofthe layer 12 prevents such short circuits from disrupting theperformance of the device by allowing insulating oil to flow into suchpin holes.

Layer 12 serves another important function when it has an index ofrefraction different than air. The presence of oil 12 over theconductive layer 10 means light propagating from the right will bemodulated more than it would be if only air was present. The reasonbeing is that for the same magnitude of surface deformation the opticalpath changes are proportional to the refraction index of the mediumadjacent to the surface.

Power supply 11 of FIG. 2 provides DC voltage of one polarity to form adeformation image on the surface of the elastomer. The polarity requireddepends upon the nature of the photoconductor. Power supply 11 must becapable of being turned off to erase the image, or, undergo a shift inpolarity to more rapidly erase the image. For a television type ofpicture wherein approximately 30 images per second are formed, storedand erased, the power supply must be capable of undergoing such cycleswith appropriate speed. The extent of the deformation and the rapiditywith which information may be erased is dependent upon the voltagessupplied by the power supply. The stability of the voltage output of thepower supply must be great enough to prevent unwanted erasure of theimage. An alternate scheme for erasing the surface deformation image isto position a strobe light at the left in FIG. 2 to flood thephotoconductive layer 8 with light thereby erasing the modulated fieldpattern across the structure set up by the imagewise light. Thisoperation is appropriate as long as the fields across the elastomerlayer 9 are below a level causing the surface deformations to be locked.

The embodiment in FIG. 3 employs a very thick conductive liquid 16 incontact with elastomer 15 to provide the necessary electric field acrossthe elastomer/- photoconductor sandwich. The other components of theapparatus of FIG. 3 are similar to those in FIGS. 1 and 2. That is,substrate 12 may be transparent or opaque and in turn may or may not beconductive. Conductive layer 13 must be present if substrate layer 12 isnot conductive. If substrate 12 is transparent then conductive layer 13will normally also be transparent. Coated on the conductive layer 13 arethe photoconductor layer 14 and the elastomer layer 15.

The thick conductive liquid 16 in FIG. 3 may or may not be transparent.Non-transparent conductive fluids include mercury, room-temperaturemolten galliumindium alloys, etc. Transparent fluids include water towhich conductive impurities have been added. If transparent, the fluid16 should have a substantially different refractive index than theelastomer 15 in order that deformations of the elastomer surface willphase modulate the illuminating light. A transparent fluid may also beused for reflection, which may be enhanced by placing a thin flexibletransparent layer on the elastomer 15 having a substantially differentrefractive index than either the elastomer or the transparent conductingfluid. Window layer 18 could be of normal optical property glass whichcontains the conductive fluid against the elastomer layer 15. Powersupply 17 supplies the necessary operating potential to the apparatus inFIG. 3. It is noted that most conducting transparent fluids will undergoelectrolysis in a DC electric field. This is undesirable because itleads to a deterioration of the operating components of the apparatus,as well as the evolution of gas. Thus, operation with conductivetransparent fluids would normally require the use of an AC field acrossthe elastomerlphotoconductor sandwich.

The fourth embodiment is illustrated in FIG. 4. This embodiment isessentially identical to the embodiment illustrated in FIG. 3, exceptthat the thick conductive layer 16 in FIG. 3 is replaced by a conductivegas 22 and requires an electrode 23 which may be a transparentconducting window. The conductive gas in cavity 22 may be obtained bymeans of a glow discharge through a low pressure gas of a fewmillimeters of mercury pressure, or by means of a low pressure aredischarge which commonly takes place at a few microns of mercurypressure. The gas may also be ionized by means of intense radioacitvityin or near a low pressure gas 22 or radio frequency excitation of thegas in cavity 22 or other techniques for producing a conductive gaseousplasma well known in the art. Charging of the elastomer surface 21 mayalso take place if gas 22 is at a sufficiently high vacuum and containsa source of thermally excited electrons, such as a heated tungstenfilament, which is directed against the elastomer surface. This may be ascanned beam as from an electron gun, or an unscanned beam, or from amultiplicity of electron emitting sources. A reflective layer may alsobe placed over layer 21 on the surface interface between layers 21 and22.

Apart from the conductive gas 22 in FIG. 4, the components thereof aresimilar to that as shown in FIG. 3. That is, substrate 18 would have aconducting layer 19 thereon with transparency or not as set forth above.Photoconductive layer 20 and elastomer layer 21 are placed over theconductive layer 19. Here, however, the conductive gas 22 may be between0.1 microns thick to an indefinite thickness. As set forth above,electrode 23 may be a separate electrode or may be coupled to atransparent conducting window to contain the conductive gas against theelastomer layer 21. The container for withholding the conductive gas 22from escaping would, of course, have to be airtight to contain the gasat the necessary level of vacuum.

The embodiment of FIG. 4 is particularly suited for holographicinterferometry because the input light can be transmitted through it toform a composite image with the output light. Therefore, aholographically reconstructed image of an object may be superimposedupon the actual image of the object to obtain interference fringes as aresult of dimensional changes.

Apart from comprising a novel imaging technique for imaging on anelastomer layer, the embodiment in FIG. 4 teaches a novel technique forcharging a surface without the use of the prior art corona dischargingdevices such as a corotron or a scorotron. The limitations of thecorotron and the scorotron are that the power requirement is high inrelation to the density of charge placed on the receptive layer.Further, corotrons and scorotrons being corona discharge devices mustnormally have a relative motion between the corona discharge device andthe receptive layer. In prior art devices such as normally utilized inxerographic machines, an electrophotographic drum such as an aluminumdrum overcoated with selenium, is rotated about a central axis past acorona discharge device such as the corotron or scorotron hereinaboveset forth. Additionally, the corona discharge device could be advancedpast a receptive layer, for example, in a situation where the receptivelayer is flat with respect to the path of movement of the coronadischarge device. Further, the fact that the prior art corona dischargedevices operate in a normal room environment, that is, with normal airof varying humidities, the charge laid upon a receptive layer is not asaccurate as could be desired. The embodiment set forth in FIG. 4,however, overcomes these disadvantages by utilizing the conductive gasin a predetermined vacuum, the level of charge placed upon a receptivelayer can be precisely determined. If the conductive gas is coupled to avacuum pump, the evacuated pressure and/or the potential applied to theelectrode 23 may be controlled to specifically predetermine the chargegenerated on the receiving layer.

A number of variations of the various elements may be substituted forthose used in the imaging devices set forth above in the embodimentsdisclosed in FIGS. 1 to 4. Thus, any one of any combination of theelements hereinafter described may be substituted for a correspondingelement hereinabove described.

With respect to the photoconductive layers hereinabove described, inaddition to the brilliant green dye produced by the J. T. Baker ChemicalCo. which is added to the poly-n-vinyl carbazole photoconductor tosensitize it for red light, other dyes may also be used forsensitization, such as trinitro-9-fluorene for blue light sensitivity.Finely ground pigments such as phthalocyanine may also be added to thepoly-n-vinyl carbazole to obtain visible light sensitivity. Otherorganic photocon ductors known in the art may also be utilizedeffectively. In addition, non-organic photoconductors, such as seleniumand selenium alloys, may also be used.

Adjacent photoconductor and elastomer layers may be replaced by a singlelayer of a photoconductive elastomer under some circumstances, in allembodiments hereinabove set forth. For example, the elastomer made bycombining sylgard 184 with dimethylpolysiloxane oils may be madephotoconductive for blue or ultraviolet light by addingp-phenylenediamine, indoform and Calco oil orange dye manufactured bythe American Cyanamid Company prior to the curing thereof.

With respect to the elastomer layers, a thin elastomer layer is capableof undergoing appreciable elastic deformation for only a limitedbandwidth of spatial frequencies. Its response outside this bandwidth isquite limited. The spatial frequency response of the elastomer may bebroadened or made multiply peaked by replacing the single elastomerlayer with a multiply layered apparatus as illustrated in FIG. 5. Eachof these layers 25, 26, 27 and 28 will have a different limited spatialfrequency response, but the combination of layers will have a broad ormultiply peaked spatial frequency response. In general, it will be notedthat the thickest layer 25 will be placed closest to the photoconductorand the thinnest layer 28 will have the deformable surface. Two or moreof such layers may be used as desired. As described previously, each ofthese layers may also be photoconductive, eliminating the need for aseparate photoconductor and in some instances enhancing the resolutionof the device.

It should also be noted that in addition to controlling the thickness ofthe elastomer layer to peak its spatial frequency response for a givenspatial frequency band width, its elastic modulus will also becontrolled to obtain deformations commensurate with that spatialfrequency bandwidth. Materials of lower elastic modulus are capable ofgreater elastic deformations. On the other hand, materials of higherelastic modulus may be more quickly erased. Such factors must be takeninto account when designing the apparatus for speed or greaterdeformation.

In several of the above embodiments, there is described the reflectionof light from the elastomer surface. Numerous methods known in the artare available fo enhancing such reflection. In addition to these, thepreviously mentioned thin layers of gold or indium, and/or othersuitable metals, vacuum deposited on the surface of the elastomerprovide a highly reflective surface that is sufficiently smooth to causelittle optical noise. These metal depositions do not appear toappreciably change the elastic behavior or the electrical insulatingproperties of the elastomer surface, but it greatly enhances thereflective power of such surfaces.

It has hereinabove been set forth that the elastomer surfaces asdescribed herein may be used for the recording, storage and erasure ofimage information over a great many cycles, provided that the electricfields across the elastomer are not allowed to become excessively great.When these fields do become great enough that the deformations of theelastomer surface exceed the elastic limit of the elastomer, it has beenobserved that the image is permanently recorded on the elastomer. Theupper limit on the electric field applied to the previously mentioneddimethylpolysiloxane siliconegel is observed to be about 100 volts permicron. While for many systems this is regarded as undesirable, thereare those in which it is also desired to record a permanent image. Thus,the cyclic properties of the elastomer may be used in an attempt toobtain a satisfactory image, which is then permanently recorded by anover voltage application.

FIGS. 6 through 10 show actual physical embodiments of imaging systemswhich could utilize the inventive principles of the present invention.FIG. 6a, for example, shows a frost or screened frost imaging techniquewith the elastomer sandwich. A light source would impinge upon anobject, the reflected light from which would be focused onto the imagingsandwich. The elastomer surface would record the image as set forth inthe embodiments of FIGS. 1 to 4. Readout of the imaging sandwich iseffected in FIG. 6b. The light source would illuminate the elastomersurface of the sandwich, the reflected light from which would bereflected away from the elastomer surface in the unfrosted areas, whilethe light impinging thereon would be scattered when reflected by thefrosted area of the image. Such scattered light from the frosted areaswould enter the lens and would form an image at the image plane. Forthis image, frosted areas would appear right, unfrosted areas dark,yielding a positive image having bright and dark areas corresponding tothose of the original object.

If the light source were a coherent light source as from a laser, thesystem set forth in FIG. 6 could be utilized to record a hologram. Thatis, the light source in FIG. 6a would be extended to impinge directlyupon the imaging sandwich as a reference beam to coact with the objectmodulated beam from the object to form a holographic image at theimaging sandwich. Upon reconstruction, the light source would be asimilar light source which would impinge upon the imaging sandwich asindicated in FIG. 6b. In FIG. 6b, however, the lens would be unnecessaryto form the reconstructed image.

The apparatus in FIGS. 6a and 6b are pertinent to the embodiments shownin FIGS. 1 to 4. With regard to the embodiemnt shown in FIG. 2, ifconductor 10 is transparent, the readout light may be incident fromeither the left or the right. If the layer 10 is opaque, the readoutlight may be incident from the left. In this latter case, the image maybe readout at the same time the image is being recorded. With regard tothe embodiment shown in FIG. 3, if fluid 16 is transparent, the readoutlight may be incident from either the right or the left. If the fluid isopaque, the readout light must be incident from the left.

FIG. 7 of the present application shows another structure which utilizesthe principles of the present invention. In a manner similar to that forFIG. 6a, the light source impinges upon the object, the reflection fromwhich is imaged by the lens onto the imaging device. With the techniqueutilized in FIGS. 1 to 4, the elastomer in the presence of theelectrical field records the image impinged thereon. Uponreconstruction, in FIG. 7, the light source now illuminates the recordedimage on the elastomer layer. The reflection from the elastomer layer isgathered by the lens which images the reflected image onto a plane.Between the plane and the lens is a focus point for the lens which, bythe use of a spatial filter, causes a positive or negative image to begenerated at the image plane. That is, a frost image reflects highfrequency spatial frequencies while the unfrosted areas reflect very lowfrequency spatial frequencies. Thus, a solid spatial frequency filterplaced at the focal point for the lens filters the low frequency spatialsignals while allowing the high frequency spatial signals to be passedand imaged on the image plane as a positive image. For a negative image,an annular spatial filter is utilzied which filters the high frequencyspatial signals while passing the low frequency spatial frequencysignals. The embodiments shown in FIG. 7 are applicable to theembodiments set forth in FIGS. 1 to 4 and are additionally applicable inthe production of a hologram as set forth above.

FIG. 8 shows an additional embodiment utilizing the principles of thepresent invention, the image thereof being recorded in a manner similarto that set forth in FIG. 6a. Upon reconstruction, however, the lightsource would be transmitted through the elastomer layer rather thanreflecting from it as set forth in FIGS. 6 and 7. Again, for either apositive or negative image, the particular spatial filter is required.This embodiment is pertinent to FIGS. 1 through 4 as were theembodiments in FIGS. 6 and 7. With respect to FIG. 2, the embodimenttherein is to be utilized only if the conductive layer 10 istransparent. With respect to the embodiment in FIG. 3, the embodimenttherein can be utilized only if the conductive fluid 16 is transparent.

FIG. 9 shows apparatus utilizing the principles of the present inventionwherein the construction and reconstruction steps occur simultaneouslywith similar or dif ferent light sources. That is, light from an objectilluminated with light of a given wavelength and intensity is focused onthe photoconductor of the imaging sandwich. Simultaneously, light of apossibly different wavelength and/or intensity is reflected from thecoated surface of the elastomer. This image is converted to an intensityimage at the image plane as was set forth above in conjunction with FIG.6. The apparatus of FIG. 9 can be extended as was the apparatus of FIGS.6 and 7 for the construction of a hologram. That is, in FIG. 9 theillumination light source would not only be impinged upon the object togenerate an object modulated wavefront, but would be impinged upon theimaging sandwich as a reference beam. Then, at the surface of theelastomer, a hologram would be constructed in accordance with the objectand reference wavefronts. Of course, the illumination light source mustnow be coherent as from a laser source, for example. Upon readout, acoherent light source would impinge upon the other side of the imagingsandwich, the light diffracted therefrom forming the reconstructedimage. I-lere, of course, the lens system would not be necessary. FIG. 9is pertinent to the embodiment set forth in FIG. 2 for simultaneousimage recording and readout primarily if a reasonably opaque metal isused for layer 10, or if the readout wavelength is non-actinic for thephotoconductor. That is, the photoconductive layer of the imagingsandwich cannot be sensitive to the readout light source or else thereadout light source will affect the generation of the image on theelastomer surface. If these conditions do not hold, FIG. 9 is pertinentto the embodiment set forth in FIG. 2 primarily if the image is firstformed and subsequently read out. That is, readout light would not bepresent during image forming in sufficient intensity to interfere withimage forming. FIG. 9 is also pertinent to the embodiments shown inFIGS. 1, 3 and 4 for simultaneous image recording and readout. It isalso pertinent to the use of high and low pass spatial filters,depending upon the generation of a positive or negative image.

FIG. 10 utilizes the imaging sandwich for holographic recording. In FIG.10a, a laser source would impinge upon the object by means of reflectionfrom a mirror, for example, while an unobstructed reference beam wouldimpinge upon the imaging sandwich. The modulated beam from the objectwould coact with the reference beam within the photoconductor layerforming a holographic image therein. By deleting the mirror and theobject itself, the laser source can be used to reconstruct the image foran observer as shown in FIG. 10b. Thus, FIG. 10 shows the use of theimaging sandwich to record a holographic interference pattern instead ofa focused image. Those comments set forth above for FIG. 8 would applyhere except it is noted that for readout the impinging wavefront must becoherent.

The system illustrated schematically in FIG. 11 employs a cyclic imagingmember 51 according to the present invention and preferably theembodiment represented by FIG. 2. The portion 52 represents thetransparent substrate, conductive layer and photoconductor while portion53 represents an elastomer layer overcoated with an opaque, reflective,electrically conductive layer which deforms with the elastomer. Thesystem utilizes the imaging member 51 as a buffer storage device betweendevices such as a digital and/or analog computer, the output of which isrepresented by the arrow 54, and the xerographic reproduction apparatus55. The buffer storage device permits asynchronous operation of thecomputer and xeropraphic apparatus.

Digital information is converted to analog information by the analog todigital converter 57 which develops appropriate signals for driving thecathode ray tube (CRT) 58. Conventionally, electron beam positioninformation is fed to the cRT through appropriate vertical andhorizontal deflection circuits 59 and 66, respectively, and beamintensity formation is fed to the CRT through an appropriate brightnesscircuit 61. The CRT normally includes a phosphor screen 62, or the like,which remains illuminated sufficiently long after the scanning beam haspassed to form a full frame image over its face. Alternately, the screenmay be illuminated substantially only at areas at which the scanningbeam currently resides. In either case, the member is able to record theloci of the beam and retains the information for a comparatively longperiod of time as long as an electric field is applied across theelastomer. Consequently, a two dimensional image may be formed on thesurface of the CRT by any scanning or raster pattern and besimultaneously or subsequently recorded as a surface deformation imageon member 5i. Appropriate lens elements 63 are interposed between thephotoconductor on member 51 and the screen 62 to create the surfacedeformation image. The photoconductor in the memberSl must besufficiently sensitive to respond to the relatively low levels of lightavailable from CRT displays. Selenium and selenium arsenic alloys areexamples of photoconductors having sensitivities in the order of lerg/cmwhich are capable of rapid response to the light levels associated withCRT displays.

The surface deformation image created on portion 53 of member 51 issimultaneously or subsequently read out by appropriate means such asthat including lamp 65 and lens 66. The lamp is a non-coherent lightsource of high intensity. As explained earlier, the light is diffractedby the surface deformation image, is collected by appropriate lenselements 66 and focused onto a plane tangent to drum 71. The imagetemporarily recorded on member 51 is permanently recorded by thexerographic recording system 55. Lens element 66 scans an image onmember 51 synchronously with rotation of the Xerographic drum 71. Thetemporary image is projected in a lineby-line fashion through the slotin light shield 70 to a line on drum 71 defined by point 72. Thescanning arrangement shown in representative and special considerationis given in an actual machine to compensate for changing distancesbetween lens 66 and image point 72. For example, the focal length oflens 66 may be that distance between the lens and point 72 when the lensis at the midpoint in its scanning path as shown. The amount ofout-of-focus when the lens is at other points in the scan path indicatedby the phantom lines of a lens is minimized by techniques known in theart.

The xerographic drum includes a photoreceptor coated onto a groundedconductive drum. The photoreceptor is charged by a corotron 73 and alatent electrostatic image is created on this charged surface as thedrum moves past the shield 70. The latent image is developed byappropriate apparatus such as a cascade developer 74 that poursmicroscopic toner particles onto the drum that adhere in the imageareas'The developed latent image, i.e., the toner image, is transferredto web 75 by electrostatics when corotron 76 deposits charge ofappropriate polarity on the back side of the web. The toner image ispermanently fixed to the web by heating the toner as with fuser 77. Thedrum surface is cleaned by means 78, e.g., a brush, flooded with lightby lamp 79 and recharged by corotron '73 to prepare for the formation ofanother toner image.

When two or more imaging members 51 are arranged in parallel, one can beused to record information generated on the CRT while other imagingmembers are being read out by having their recorded informationprojected onto a recording medium such as the xerographic apparatus.

The above described systems are highly advantageous because analog anddigital computers often generate information in irregular time intervalswhereas xerographic and other recording apparatus operate on highlyorganized information and employ fixed operating cycles. The imagedevice 51 bridges the gap because it is able to: record irregularlygenerated information; hold the information in a highly organized statefor getting into phase with the reproduction cycle of xerographic orother imaging device; rapidly erase the recorded information; andimmediately record new information.

The xerographic apparatus 55 may be replaced by other recordingmaterials and/or apparatus. For example, photographic type films havingsensitivities far too insensitive to respond to the light levelsgenerated by a CRT display may be used because the necessary energylevels can be supplied by lamp 6S. Vesicular duplicating films availablefrom the Kalvar Corp. of New Orleans, La. are examples of such films.

In the foregoing there has been disclosed methods and apparatusindicating the application of elastomers to various imaging apparatus asdescribed herein. By the use of an elastomer material, there is obtaineda fully cyclical imaging apparatus on which images may be recorded,stored for short periods of time and erased at will. In thespecification herein, specific materials and construction have beendiscussed with regard to the makeup of the imaging sandwich, but it isobvious that other construction may be available utilizing the elastomermaterial without deviating from the principles of the present invention.Therefore, while the invention has been described with reference tospecific embodiments, it will be understood by those skilled in the artthat various changes may be made and equivalents may be substituted forelements thereof without departing from the true spirit and scope of theinvention. In addition, many modifications may be made to adapt to aparticular situation without departing from the essential teachings ofthe invention.

What is claimed is:

1. Imaging apparatus comprising an imaging member comprising a layer ofphotoconductive material, an electric field deformable elastomer layerhaving a volume resistivity above about 10 ohm-cm. adjacent saidphotoconductive material layer and a deformable conductive layeradjacent said elastomer layer, said deformable conductive layercomprising gold and indium, said elastomer layer being capable ofdeforming to correspond to an electric field pattern created byalterfirst light means for generating input electromagnetic radiation towhich said imaging member photoconductive material is responsive, forobject modulating said input radiation and for exposing said imagingmember to said modulated input radiation and second light means forgenerating readout electromagnetic radiation and for directing saidreadout radiation onto said imaging member for constructing imagescorresponding to the deformations of the elastomer layer.

2. The apparatus of claim 1 wherein said second light means includeslens means for gathering readout radiation diffracted by deformed areasof the imaging memher for constructing said corresponding image.

3. The apparatus of claim 2 wherein said second light means includesspatial filter means for generating positive and negative images fromsaid readout radiation gathered by said lens.

4. The apparatus of claim 2 wherein said input and readout radiationinclude coherent radiation and said first light means includes means forsuperimposing input radiation not modulated by an object and saidmodulated input radiation onto the imaging member to expose the imagingmember to the interference pattern created by the superposition of themodulated and unmodulated input radiation.

5. The apparatus of claim ll further including means for simultaneouslydirecting said input and readout radiation onto said imaging member.

6. The apparatus of claim 1 wherein one of said input and outputradiation includes coherent radiation and the other includesnon-coherent radiation.

7. The apparatus of claim 1 wherein said imaging member is transparentand said first and second light means include means for directing saidinput and readout radiation onto said imaging member from the same side.

8. The apparatus of claim 1 wherein said flexible conductive member issubstantially reflective of said readout radiation and said substrate issubstantially transparent to said input radiation.

) imaging apparatus comprising an imaging member comprising a layer ofphotoconductive material, an electric field deformable elastomer layerhaving a volume resistivity above about 10* ohm-cm. adjacent saidphotoconductive material layer and a deformable conductive layeradjacent said elastomer layer, said deformable conductive layercomprising gold and indium, said elastomer layer being capable ofdeforming to correspond to an electric field pattern created by alteringan electrical field across said elastomer layer by exposing thephotoconductive material to electromagnetic radiation to which it isresponsive;

a cathode ray tube for generating on a screen radiation to which thephotoconductive material of said imaging member is responsive and meansfor projecting radiation generated on said screen onto said imagingmember to deform the elastomer layer according to patterns formed bysaid radiation.

10. The apparatus of claim 9 further including means for directingreadout electromagnetic radiation onto said deformable conductive layerto construct an image corresponding to deformations on the elastomerlayer.

11. The apparatus of claim further including recording means forrecording the constructed image corresponding to deformations on theelastomer layer.

12. The apparatus of claim 11 wherein said recording means includesxerographic recording apparatus.

13. The apparatus of claim 12 wherein said xerographic recordingapparatus includes a rotating xerographic drum.

14. The apparatus as defined in claim 1 wherein said imaging memberfurther includes a substrate for supporting the layers of said imagingmember.

15. The apparatus as defined in claim 14 wherein said substrate is atransparent conductive substrate.

16. The apparatus as defined in claim 1 wherein said imaging memberfurther includes a layer of insulating liquid overlying said deformableconductive layer.

17. The apparatus as defined in claim 1 wherein said imaging memberfurther includes means for spatially modulating an electric field acrosssaid elastomer layer at a frequency within the spatial frequencydeformation capability of the elastomer layer.

18. The apparatus as defined in claim 9 wherein said imaging memberfurther includes a substrate for supporting the layers of said imagingmember.

19. The apparatus as defined in claim 18 wherein said substrate is atransparent conductive substrate.

20. The apparatus as defined in claim 9 wherein said imaging memberfurther includes a layer of insulating liquid overlying said deformableconductive layer.

21. The apparatus as defined in claim 9 wherein said imaging memberfurther includes means for spatially modulating an electric field acrosssaid elastomer layer at a frequency within the spatial frequencydeformation capability of the elastomer layer.

22. Imaging apparatus comprising an imaging member comprising anelectric field deformable elastomer layer having a volume resistivityabove about 10 ohm-cm, said elastomer layer including photoconductivematerial, and a deformable conductive layer overlying said elastomerlayer, said deformable conductive layer comprising gold and indium, saidelastomer layer being capable of deforming to correspond to an electricfield pattern created by altering an electrical field across saidelastomer layer by exposing said photoconductive material toelectromagnetic radiation to which it is responsive;

first light means for generating input electromagnetic radiation towhich said imaging member photoconductive material is responsive, forobject modulating said input radiation and for exposing said imagingmember to said modulated input radiation and second light means forgenerating readout electromagnetic radiation and for directing saidreadout radiation onto said imaging member for constructing imagescorresponding to the deformations of the elastomer layer.

23. The apparatus as defined in claim 22 wherein said imaging memberfurther includes a substrate for supporting the layers of said imagingmember.

24. The apparatus as defined in claim 23 wherein said substrate is atransparent conductive substrate.

25. The apparatus as defined in claim 22 wherein said imaging memberfurther includes a layer of insulating liquid overlying said deformableconductive layer.

26. The apparatus as defined in claim 22 wherein said imaging memberfurther includes means for spatially modulating an electric field acrosssaid elastomer layer at a frequency within the spatial frequencydeformation capability of the elastomer layer.

27. The apparatus as defined in claim 22 wherein said second light meansincludes lens means for gathering readout radiation diffracted bydeformed areas of the imaging member for constructing said correspondingimage.

28. The apparatus as defined in claim 27 wherein said second light meansincludes spatial filter means for generating positive and negativeimages from said readout radiation gathered by said lens.

29. The apparatus as defined in claim 22 wherein said input and readoutradiation include coherent radiation and said first light means includesmeans for superimposing input radiation not modulated by an object andsaid modulated input radiation onto the imaging member to expose theimaging member to the interference pattern created by the superpositionof the modulated and unmodulated input radiation.

30. The apparatus as defined in claim 22 further including means forsimultaneously directing said input and readout radiation onto saidimaging member.

31. The apparatus as defined in claim 22 wherein one of said input andoutput radiation includes coherent radiation and the other includesnon-coherent radiation.

32. The apparatus as defined in claim 22 wherein said imaging member istransparent and said first and second light means include means fordirecting said input and readout radiation onto said imaging member fromthe same side.

33. The apparatus as defined in claim 23 wherein said deformableconductive layer is substantially reflective of said readout radiationand said substrate is substantially transparent to said input radiation.

34. Imaging apparatus comprising an imaging member comprising anelectric field deformable elastomer layer having a volume resistivityabove about 10 ohm-cm, said elastomer layer including photoconductivematerial, and a deformable conductive layer overlying said elastomerlayer, said deformable conductive layer comprising gold and indium, saidelastomer layer being capable of deforming to correspond to an electricfield pattern created by altering an electrical field across saidelastomer layer by exposing said photoconductive material toelectromagnetic radiation to which it is responsive;

a cathode ray tube for generating on a screen radiation to which thephotoconductive material of said imaging member is responsive and meansfor projecting radiation generated on said screen onto said imagingmember to deform the elastomer layer according to patterns formed bysaid radiation.

35. The apparatus as defined in claim 34 wherein said imaging memberfurther includes a substrate for sup porting the layers of said imagingmember.

36. The apparatus as defined in claim 35 wherein said substrate is atransparent conductive substrate.

37. The apparatus as defined in claim 34 wherein said imaging memberfurther includes a layer of insulating liquid overlying said deformableconductive layer.

38. The apparatus as defined in claim 34 wherein said imaging memberfurther includes means for spatially modulating an electric field acrosssaid elastomer layer at a frequency within the spatial frequencydeformation capability of the elastomer layer.

39. The apparatus as defined in claim 34 further including means fordirecting readout electromagnetic radiation onto said deformableconductive layer to construct an image corresponding to deformations onthe elastomer layer.

40. The apparatus as defined in claim 34 further including recordingmeans for recording the constructed image corresponding to deformationson the elastomer layer.

41. The apparatus as defined in claim 40 wherein said recording meansincludes xerographic recording apparatus.

42. The apparatus as defined in claim 41 wherein said xerographicrecording apparatus includes a rotating xerographic drum.

43. Imaging apparatus comprising an imaging member comprising asubstrate, a layer of photoconductive material overlying said substrate,an electric field deformable elastomer layer having a volume resistivityabove about ohm-cm. adjacent said photoconductive material layer and adeformable conductive layer adjacent said elastomer layer, saiddeformable conductive layer comprising first and second metal materials,wherein said first metal material is chosen from the group consisting ofgold, aluminium, silver, magnesium, copper, cobalt, iron, chromium andnickel, said second metal material is chosen from the group consistingof indium, gallium, cadmium, mercury and lead and said elastomer layerbeing capable of deforming to correspond to an electric field patterncreated by altering an electrical field across said elastomer layer byexposing the photoconductive material to electromagnetic radiation towhich it is responsive;

first light means for generating input electromagnetic radiation towhich said imaging member photoconductive material is responsive, forobject modulating said input radiation and for exposing said imagingmember to said modulated input radiation and second light means forgenerating readout electromagnetic radiation and for directing saidreadout radiation onto said imaging member for constructing imagescorresponding to the deformations of the elastomer layer.

44. imaging apparatus comprising an imaging member comprising asubstrate, an elec tric field deformable elastomer layer having a volumeresistivity above about 10 ohm-cm. overlying said substrate, saidelastomer layer including photoconductive material and a deformableconductive layer adjacent said elastomer layer, said deformableconductive layer comprising first and second metal materials, whereinsaid first metal material is chosen from the group consisting of gold,aluminium, silver, magnesium, copper, cobalt, iron, chromium and nickel,said second metal material is chosen from the group consisting ofindium, gallium, cadmium, mercury and lead, and said elastomer layerbeing capable of deforming to correspond to an electric field patterncreated by altering an electric field across said elastomer layer byexposing the photoconductive material to electromagnetic radiation towhich it is responsive;

first light means for generating input electromagnetic radiation towhich said imaging member photoconductive material is responsive, forobject modulating said input radiation and for exposing said imagingmember to said modulated input radiation and second light means forgenerating readout electromagnetic radiation and for directing saidreadout radiation onto said imaging member for constructing imagescorresponding to the deformations of the elastomer layer.

45. Imaging apparatus comprising an imaging member comprising asubstrate, a layer of photoconductive material overlying said substrate,an electric field deformable elastomer layer having a volume resistivityabove about 10 ohm-cm. adjacent said photoconductive material layer anda deformable conductive layer adjacent said elastomer layer, saiddeformable conductive layer comprising first and second metal materials,wherein said first metal material is chosen from the group consisting ofgold, aluminium, silver, magnesium, copper, cobalt, iron, chromium andnickel, said second metal material is chosen from the group consistingof indium, gallium, cadmium, mercury and lead and said elastomer layerbeing capable of deforming to correspond to an electric field patterncreated by altering an electrical field across said elastomer layer byexposing the photoconductive material to electromagnetic radiation towhich it is responsive;

a cathode ray tube for generating on a screen rediation to which thephotoconductive material of said imaging member is responsive and meansfor projecting radiation generated on said screen onto said imagingmember to deform the elastomer layer according to patterns formed bysaid radiation.

46. Imaging apparatus comprising an imaging member comprising asubstrate, an elec tric field deformable elastomer layer having a volumeresistivity above about 10 ohm-cm. overlying said substrate, saidelastomer layer including photoconductive material and a deformableconductive layer adjacent said elastomer layer, said deformableconductive layer comprising first and second metal materials, whereinsaid first metal material is chosen from the group consisting of gold,aluminium, silver, magnesium, copper, cobalt, iron, chromium and nickel,said second metal material is chosen from the group consisting ofindium, gallium, cadmium, mercury and lead, and said elastomer layerbeing capable of deforming to correspond to an electric field patterncreated by altering an electric field across said elastomer layer byexposing the photoconductive material to electromagnetic radiation towhich it is responsive;

a cathode ray tube for generating on a screen radiation to which thephotoconductive material of said imaging member is responsive and meansfor projecting radiation generated on said screen onto said imagingmember to deform the elastomer layer according to patterns formed bysaid radiation.

47. Imaging apparatus comprising 7 an imaging member comprising asubstrate, a layer of photoconductive material overlying said substrate,an electric field deformable elastomer layer having a volume resistivityabove about 10 ohm-cm. adjacent said photoconductive material layer anda deformable layer of conductive gas adjacent said deformable elastomerlayer, said conductive layer including means for ionizing saidconductive gas, and said elastomer layer being capable of deforming tocorrespond to an electric field pattern created by altering anelectrical field across said elastomer layer by exposing said member toelectromagnetic radiation to which said photoconductive material isresponsive;

first light means for generating input electromagnetic radiation towhich said imaging member photoconductive material is responsive, forobject modulating said input radiation and for exposing said imagingmember to said modulated input radiation and second light means forgenerating readout electromagnetic radiation and for directing saidreadout radiation onto said imaging member for constructing imagescorresponding tothe deformations of the elastomer layer.

48. Imaging apparatus comprising an imaging member comprising asubstrate, an electric field deformable elastomer layer having a volumeresistivity above about 10 ohm-cm. overlying said substrate, saidelastomer layer including photoconductive material and a deformablelayer of conductive gas adjacent said deformable elastomer layer, saidconductive gas layer including means for ionizing said conductive gas,and said elastomer layer being capable of deforming to correspond to anelectric field pattern created by altering an electric field across saidelastomer layer by exposing said member to electromagnetic radiation towhich said photoconductive material is responsive;

first light means for generating input electromagnetic radiation towhich said imaging member photoconductive material is responsive, forobject modulating said input radiation and for exposing said imagingmember to said modulated input radiation and second light means forgenerating readout electromagnetic radiation and for directing saidreadout radiation onto said imaging member for constructing imagescorresponding to the deformations of the elastomer layer.

49. Imaging apparatus comprising an imaging member comprising asubstrate, a layer of photoconductive material overlying said substrate,an electric field deformable elastomer layer having a volume resistivityabove about 10 ohm-cm. adjacent said photoconductive material layer anda deformable layer of conductive gas adjacent said deformable elastomerlayer, said conductive gas layer including means for ionizing saidconductive gas, and said elastomer layer being capable of deforming tocorrespond to an electric field pattern created by altering anelectrical field across said elastomer layer by exposing said member toelectromagnetic radiation to which said photoconductive material isresponsive;

a cathode ray tube for generating on a screen radiation to which thephotoconductive material of said imaging member is responsive and meansfor projecting radiation generated on said screen onto said imagingmember to deform the elastomer layer according to patterns formed bysaid radiation.

50. Imaging apparatus comprising an imaging member comprising asubstrate, an electric field deformable elastomer layer having a volumeresistivity above about 10 ohm-cm. overlying said substrate, saidelastomer layer including photoconductive material and a deformablelayer of conductive gas adjacent said deformable elastomer layer, saidconductive gas layer including means for ionizing said conductive gas,and said elastomer layer being capable of deforming to correspond to anelectric field pattern created by allowing an electric field across saidelastomer layer by exposing said member to electromagnetic radiation towhich said photoconductive material is responsive;

a cathode ray tube for generating on a screen radiation to which thephotoconductive material of said imaging member is responsive and meansfor projecting radiation generated on said screen onto said imagingmember to deform the elastomer layer according to patterns formed byUNITED STATES PATENT OFFICE CERTIFICATE OF CORRECT ION Patent No. 2'Dated October 1974 Inventor) Nicholas K. Sheridon It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 4, line 55 after "respectively" ihs ert now U.S Patent 3,7l9,483and U.S. Patent 3,698,893, respectively Column 6-, line '7 "ehtylene"should read ethylene Column 7, line 10 "teh" should read the Column 14,line 12 "embodiemnt" should read embodiment Column 16,- line 7 "cRT"should read CRT Claim 4, line 1 "2" should read 1 Claim 8, lihe l "1"should read l4 Signed and sealed this 31st day of December 1%74.

Attest: 'MoCOY M. GIBSON JR. c. MARSHALL DANIZ Attesting OfficerCommissioner of Patents ORM PO-IOSO (10-69) USCOMM'DC 6OS76'P69 U45.GOVIINMINT PIIIIYING OFFICE 1 "II O-JiSSL patent N 842,406 Dated October15, 1974 Inventor(s) Nicholas Sheri-don 7 It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 4, line 55 after "respectively" insert now U.S.

Patent 3,719,483 and U.S. Patent 3,698,893, respectively- Column 6',line 7 "ehtylene" should read ethylene Column 7; line 10 "teh" shouldread the Column 14, line 12 "embodiemnt" should read embodiment Columnl6,"lin-e 7 "CRT" should read C."R'I" Claim 4, line 1 "2" should read lClaim 8, line 1 "1" should read 14 Signed and sealed this 31st day ofDecember 1974.

(SI-3A1) Attest:

moor M. slssorz JR. (3, ZIARSHALL mm: Arresting Officer Commissioner ofPatents FORM I uscoMM-oc wan-Poo U- GOVRN'IINT PIIH'ING OFIICI: I I."0-in-3.

1. Imaging apparatus comprising an imaging member comprising a layer ofphotoconductive material, an electric field deformable elastomer layerhaving a volume resistivity above about 104 ohm-cm. adjacent saidphotoconductive material layer and a deformable conductive layeradjacent said elastomer layer, said deformable conductive layercomprising gold and indium, said elastomer layer being capable ofdeforming to correspond to an electric field pattern created by alteringan electrical field across said elastomer layer by exposing thephotoconductive material to electromagnetic radiation to which it isresponsive; first light means for generating input electromagneticradiation to which said imaging member photoconductive material isresponsive, for object modulating said input radiation and for exposingsaid imaging member to said modulated input radiation and second lightmeans for generating readout electromagnetic radiation and for directingsaid readout radiation onto said imaging member for constructing imagescorresponding to the deformations of the elastomer layer.
 2. Theapparatus of claim 1 wherein said second light means includes lens meansfor gathering readout radiation diffracted by deformed areas of theimaging member for constructing said corresponding image.
 3. Theapparatus of claim 2 wherein said second light means includes spatialfilter means for generating positive and negative images from saidreadout radiation gathered by said lens.
 4. The apparatus of claim 2wherein said input and readout radiation include coherent radiation andsaid first light means includes means for superimposing input radiationnot modulated by an object and said modulated input radiation onto theimaging member to expose the imaging member to the interference patterncreated by the superposition of the modulated and unmodulated inputradiation.
 5. The apparatus of claim 1 further including means forsimultaneously directing said input and readout radiation onto saidimaging member.
 6. The apparatus of claim 1 wherein one of said inputand output radiation includes coherent radiation and the other includesnon-coherent radiation.
 7. The apparatus of claim 1 wherein said imagingmember is transparent and said first and second light means includemeans for directing said input and readout radiation onto said imagingmember from the same side.
 8. The apparatus of claim 1 wherein saidflexible conductive member is substantially reflective of said readoutradiation and said substrate is substantially transparent to said inputradiation.
 9. Imaging apparatus comprising an imaging member comprisinga layer of photoconductive material, an electric field deformableelastomer layer having a volume resistivity above about 104 ohm-cm.adjacent said photoconductive material layer and a deformable conductivelayer adjacent said elastomer layer, said deformable conductive layercomprising gold and indium, said elastomer layer being capable ofdeforming to correspond to an electric field pattern created by alteringan electrical field across said elastomer layer by exposing thephotoconductive material to electromagnetic radiation to which it isresponsive; a cathode ray tube for generating on a screen radiation towhich the photoconductive material of said imaging member is responsiveand means for projecting radiation generated on said screen onto saidimaging member to deform the elastomer layer according to patternsformed by said radiation.
 10. The apparatus of claim 9 further includingmeans for directing readout electromagnetic radiation onto saiddeformable conductive layer to construct an image corresponding todeformations on the elastomer layEr.
 11. The apparatus of claim 10further including recording means for recording the constructed imagecorresponding to deformations on the elastomer layer.
 12. The apparatusof claim 11 wherein said recording means includes xerographic recordingapparatus.
 13. The apparatus of claim 12 wherein said xerographicrecording apparatus includes a rotating xerographic drum.
 14. Theapparatus as defined in claim 1 wherein said imaging member furtherincludes a substrate for supporting the layers of said imaging member.15. The apparatus as defined in claim 14 wherein said substrate is atransparent conductive substrate.
 16. The apparatus as defined in claim1 wherein said imaging member further includes a layer of insulatingliquid overlying said deformable conductive layer.
 17. The apparatus asdefined in claim 1 wherein said imaging member further includes meansfor spatially modulating an electric field across said elastomer layerat a frequency within the spatial frequency deformation capability ofthe elastomer layer.
 18. The apparatus as defined in claim 9 whereinsaid imaging member further includes a substrate for supporting thelayers of said imaging member.
 19. The apparatus as defined in claim 18wherein said substrate is a transparent conductive substrate.
 20. Theapparatus as defined in claim 9 wherein said imaging member furtherincludes a layer of insulating liquid overlying said deformableconductive layer.
 21. The apparatus as defined in claim 9 wherein saidimaging member further includes means for spatially modulating anelectric field across said elastomer layer at a frequency within thespatial frequency deformation capability of the elastomer layer. 22.Imaging apparatus comprising an imaging member comprising an electricfield deformable elastomer layer having a volume resistivity above about104 ohm-cm., said elastomer layer including photoconductive material,and a deformable conductive layer overlying said elastomer layer, saiddeformable conductive layer comprising gold and indium, said elastomerlayer being capable of deforming to correspond to an electric fieldpattern created by altering an electrical field across said elastomerlayer by exposing said photoconductive material to electromagneticradiation to which it is responsive; first light means for generatinginput electromagnetic radiation to which said imaging memberphotoconductive material is responsive, for object modulating said inputradiation and for exposing said imaging member to said modulated inputradiation and second light means for generating readout electromagneticradiation and for directing said readout radiation onto said imagingmember for constructing images corresponding to the deformations of theelastomer layer.
 23. The apparatus as defined in claim 22 wherein saidimaging member further includes a substrate for supporting the layers ofsaid imaging member.
 24. The apparatus as defined in claim 23 whereinsaid substrate is a transparent conductive substrate.
 25. The apparatusas defined in claim 22 wherein said imaging member further includes alayer of insulating liquid overlying said deformable conductive layer.26. The apparatus as defined in claim 22 wherein said imaging memberfurther includes means for spatially modulating an electric field acrosssaid elastomer layer at a frequency within the spatial frequencydeformation capability of the elastomer layer.
 27. The apparatus asdefined in claim 22 wherein said second light means includes lens meansfor gathering readout radiation diffracted by deformed areas of theimaging member for constructing said corresponding image.
 28. Theapparatus as defined in claim 27 wherein said second light meansincludes spatial filter means for generating positive and negativeimages from said readout radiation gathered by said lens.
 29. Theapparatus as defined in claim 22 wherein said input and readoutradiation include coherent radiation And said first light means includesmeans for superimposing input radiation not modulated by an object andsaid modulated input radiation onto the imaging member to expose theimaging member to the interference pattern created by the superpositionof the modulated and unmodulated input radiation.
 30. The apparatus asdefined in claim 22 further including means for simultaneously directingsaid input and readout radiation onto said imaging member.
 31. Theapparatus as defined in claim 22 wherein one of said input and outputradiation includes coherent radiation and the other includesnon-coherent radiation.
 32. The apparatus as defined in claim 22 whereinsaid imaging member is transparent and said first and second light meansinclude means for directing said input and readout radiation onto saidimaging member from the same side.
 33. The apparatus as defined in claim23 wherein said deformable conductive layer is substantially reflectiveof said readout radiation and said substrate is substantiallytransparent to said input radiation.
 34. Imaging apparatus comprising animaging member comprising an electric field deformable elastomer layerhaving a volume resistivity above about 104 ohm-cm., said elastomerlayer including photoconductive material, and a deformable conductivelayer overlying said elastomer layer, said deformable conductive layercomprising gold and indium, said elastomer layer being capable ofdeforming to correspond to an electric field pattern created by alteringan electrical field across said elastomer layer by exposing saidphotoconductive material to electromagnetic radiation to which it isresponsive; a cathode ray tube for generating on a screen radiation towhich the photoconductive material of said imaging member is responsiveand means for projecting radiation generated on said screen onto saidimaging member to deform the elastomer layer according to patternsformed by said radiation.
 35. The apparatus as defined in claim 34wherein said imaging member further includes a substrate for supportingthe layers of said imaging member.
 36. The apparatus as defined in claim35 wherein said substrate is a transparent conductive substrate.
 37. Theapparatus as defined in claim 34 wherein said imaging member furtherincludes a layer of insulating liquid overlying said deformableconductive layer.
 38. The apparatus as defined in claim 34 wherein saidimaging member further includes means for spatially modulating anelectric field across said elastomer layer at a frequency within thespatial frequency deformation capability of the elastomer layer.
 39. Theapparatus as defined in claim 34 further including means for directingreadout electromagnetic radiation onto said deformable conductive layerto construct an image corresponding to deformations on the elastomerlayer.
 40. The apparatus as defined in claim 34 further includingrecording means for recording the constructed image corresponding todeformations on the elastomer layer.
 41. The apparatus as defined inclaim 40 wherein said recording means includes xerographic recordingapparatus.
 42. The apparatus as defined in claim 41 wherein saidxerographic recording apparatus includes a rotating xerographic drum.43. Imaging apparatus comprising an imaging member comprising asubstrate, a layer of photoconductive material overlying said substrate,an electric field deformable elastomer layer having a volume resistivityabove about 104 ohm-cm. adjacent said photoconductive material layer anda deformable conductive layer adjacent said elastomer layer, saiddeformable conductive layer comprising first and second metal materials,wherein said first metal material is chosen from the group consisting ofgold, aluminium, silver, magnesium, copper, cobalt, iron, chromium andnickel, said second metal material is chosen from the group consistingof indium, gallium, cadmium, mercury and lead and said elastomer layerbeing capable of deforming tO correspond to an electric field patterncreated by altering an electrical field across said elastomer layer byexposing the photoconductive material to electromagnetic radiation towhich it is responsive; first light means for generating inputelectromagnetic radiation to which said imaging member photoconductivematerial is responsive, for object modulating said input radiation andfor exposing said imaging member to said modulated input radiation andsecond light means for generating readout electromagnetic radiation andfor directing said readout radiation onto said imaging member forconstructing images corresponding to the deformations of the elastomerlayer.
 44. Imaging apparatus comprising an imaging member comprising asubstrate, an electric field deformable elastomer layer having a volumeresistivity above about 104 ohm-cm. overlying said substrate, saidelastomer layer including photoconductive material and a deformableconductive layer adjacent said elastomer layer, said deformableconductive layer comprising first and second metal materials, whereinsaid first metal material is chosen from the group consisting of gold,aluminium, silver, magnesium, copper, cobalt, iron, chromium and nickel,said second metal material is chosen from the group consisting ofindium, gallium, cadmium, mercury and lead, and said elastomer layerbeing capable of deforming to correspond to an electric field patterncreated by altering an electric field across said elastomer layer byexposing the photoconductive material to electromagnetic radiation towhich it is responsive; first light means for generating inputelectromagnetic radiation to which said imaging member photoconductivematerial is responsive, for object modulating said input radiation andfor exposing said imaging member to said modulated input radiation andsecond light means for generating readout electromagnetic radiation andfor directing said readout radiation onto said imaging member forconstructing images corresponding to the deformations of the elastomerlayer.
 45. Imaging apparatus comprising an imaging member comprising asubstrate, a layer of photoconductive material overlying said substrate,an electric field deformable elastomer layer having a volume resistivityabove about 104 ohm-cm. adjacent said photoconductive material layer anda deformable conductive layer adjacent said elastomer layer, saiddeformable conductive layer comprising first and second metal materials,wherein said first metal material is chosen from the group consisting ofgold, aluminium, silver, magnesium, copper, cobalt, iron, chromium andnickel, said second metal material is chosen from the group consistingof indium, gallium, cadmium, mercury and lead and said elastomer layerbeing capable of deforming to correspond to an electric field patterncreated by altering an electrical field across said elastomer layer byexposing the photoconductive material to electromagnetic radiation towhich it is responsive; a cathode ray tube for generating on a screenrediation to which the photoconductive material of said imaging memberis responsive and means for projecting radiation generated on saidscreen onto said imaging member to deform the elastomer layer accordingto patterns formed by said radiation.
 46. Imaging apparatus comprisingan imaging member comprising a substrate, an electric field deformableelastomer layer having a volume resistivity above about 104 ohm-cm.overlying said substrate, said elastomer layer including photoconductivematerial and a deformable conductive layer adjacent said elastomerlayer, said deformable conductive layer comprising first and secondmetal materials, wherein said first metal material is chosen from thegroup consisting of gold, aluminium, silver, magnesium, copper, cobalt,iron, chromium and nickel, said second metal material is chosen from thegroup consisting of indium, gallium, cadmium, mercury and lead, and saidElastomer layer being capable of deforming to correspond to an electricfield pattern created by altering an electric field across saidelastomer layer by exposing the photoconductive material toelectromagnetic radiation to which it is responsive; a cathode ray tubefor generating on a screen radiation to which the photoconductivematerial of said imaging member is responsive and means for projectingradiation generated on said screen onto said imaging member to deformthe elastomer layer according to patterns formed by said radiation. 47.Imaging apparatus comprising an imaging member comprising a substrate, alayer of photoconductive material overlying said substrate, an electricfield deformable elastomer layer having a volume resistivity above about104 ohm-cm. adjacent said photoconductive material layer and adeformable layer of conductive gas adjacent said deformable elastomerlayer, said conductive layer including means for ionizing saidconductive gas, and said elastomer layer being capable of deforming tocorrespond to an electric field pattern created by altering anelectrical field across said elastomer layer by exposing said member toelectromagnetic radiation to which said photoconductive material isresponsive; first light means for generating input electromagneticradiation to which said imaging member photoconductive material isresponsive, for object modulating said input radiation and for exposingsaid imaging member to said modulated input radiation and second lightmeans for generating readout electromagnetic radiation and for directingsaid readout radiation onto said imaging member for constructing imagescorresponding to the deformations of the elastomer layer.
 48. Imagingapparatus comprising an imaging member comprising a substrate, anelectric field deformable elastomer layer having a volume resistivityabove about 104 ohm-cm. overlying said substrate, said elastomer layerincluding photoconductive material and a deformable layer of conductivegas adjacent said deformable elastomer layer, said conductive gas layerincluding means for ionizing said conductive gas, and said elastomerlayer being capable of deforming to correspond to an electric fieldpattern created by altering an electric field across said elastomerlayer by exposing said member to electromagnetic radiation to which saidphotoconductive material is responsive; first light means for generatinginput electromagnetic radiation to which said imaging memberphotoconductive material is responsive, for object modulating said inputradiation and for exposing said imaging member to said modulated inputradiation and second light means for generating readout electromagneticradiation and for directing said readout radiation onto said imagingmember for constructing images corresponding to the deformations of theelastomer layer.
 49. Imaging apparatus comprising an imaging membercomprising a substrate, a layer of photoconductive material overlyingsaid substrate, an electric field deformable elastomer layer having avolume resistivity above about 104 ohm-cm. adjacent said photoconductivematerial layer and a deformable layer of conductive gas adjacent saiddeformable elastomer layer, said conductive gas layer including meansfor ionizing said conductive gas, and said elastomer layer being capableof deforming to correspond to an electric field pattern created byaltering an electrical field across said elastomer layer by exposingsaid member to electromagnetic radiation to which said photoconductivematerial is responsive; a cathode ray tube for generating on a screenradiation to which the photoconductive material of said imaging memberis responsive and means for projecting radiation generated on saidscreen onto said imaging member to deform the elastomer layer accordingto patterns formed by said radiation.
 50. Imaging apparatus comprisingan imaging member comprising a substrate, an electric fIeld deformableelastomer layer having a volume resistivity above about 104 ohm-cm.overlying said substrate, said elastomer layer including photoconductivematerial and a deformable layer of conductive gas adjacent saiddeformable elastomer layer, said conductive gas layer including meansfor ionizing said conductive gas, and said elastomer layer being capableof deforming to correspond to an electric field pattern created byallowing an electric field across said elastomer layer by exposing saidmember to electromagnetic radiation to which said photoconductivematerial is responsive; a cathode ray tube for generating on a screenradiation to which the photoconductive material of said imaging memberis responsive and means for projecting radiation generated on saidscreen onto said imaging member to deform the elastomer layer accordingto patterns formed by said radiation.